Trehalulose (1-O-α-D-glucopyranosyl-D-fructose) and isomaltulose (palatinose, 6-O-α-D-glucopyranosyl-D-fructose) are known structural isomers of sucrose. These isomers are naturally found in honey in small quantities. Both of them are known as non-cariogenic sugars. However, their physical and chemical characteristics are somewhat different, in particular in view of the fact that trehalulose is more soluble in water than isomaltulose with the consequence that their use as food ingredients is different.
Both, isomaltulose and trehalulose, are also known from for instance EP 1 424 074 A1 as being heterodisaccharides, which in comparison to sucrose, show a reduced hydrolysis rate in the small intestine of human or animal consumers, thereby suggesting the provision of nutritional compositions for controlling blood sugar levels, in particular for the use in patients suffering from diabetes and glucose intolerance, or for obesity prevention. However, the document is silent on the specific role and relevance of isomaltulose and trehalulose contained in the nutritional compositions.
EP 0 483 755 B1 discloses processes to prepare compositions comprising trehalulose and isomaltulose. In particular, Pseudomonas mesoacidophila MX-45 (FERM-BP 3619) or Agrobacterium radiobacter MX-232 (FERM-BP 3620) was used to convert a sucrose containing medium into a primarily trehalulose, but also significant amounts of isomaltulose containing solution. Thus, the disclosed methods make use of the capability of the α-glucosyltransferase of either Pseudomonas mesoacidophila or Agrobacterium radiobacter to convert sucrose both into trehalulose and isomaltulose, wherein predominantly trehalulose is obtained.
EP 0 794 259 B1 discloses the preparation of a trehalulose-containing polysaccharide composition using a maltose/trehalose converting enzyme from Pseudomonas putida, Thermus ruber, Thermus aquatica or Pimelobacter to produce the trehalulose-containing composition from a sucrose solution.
EP 0 091 063 A2 discloses a process for the preparation of isomaltulose using immobilized bacterial cells, in particular cells from Protaminobacter rubrum (CBS 574.77). The process disclosed therein uses a sucrose-containing solution, which is subjected to these immobilized cells so as to obtain a primarily isomaltulose containing composition, which, however, also comprises trehalulose.
EP 1 393 637 A1 discloses agents for sustaining concentration and attentiveness, in particular food and drinks containing said agents. The document discloses products for human consumption, which are said to improve the concentration and attention due to the presence of isomaltulose contained in the product.
EP 0 983 374 B1 discloses processes for the simultaneous production of isomaltulose and/or trehalulose and betain.
All of these processes aim to produce either a trehalulose or a isomaltulose-containing composition or even pure trehalulose or isomaltulose so as to make use of the known physiological properties, in particular their non-cariogenity and their slow hydrolyses rate in the small intestine. Although isomaltulose is an attractive agent for developing products suitable to prevent and treat overweight, obesity, diabetes and other glucose or insulin metabolism-related conditions and diseases, there still remains the need to provide even more effective active ingredients.
The production of trehalulose-containing compositions, also termed vitalose, which comprise a high content of isomaltulose is for a number of applications, such as jelly or fruit juices, not desirable, since isomaltulose tends to crystallize out, in particular in applications in an aqueous surrounding. Although the preparation of compositions comprising a high content of trehalulose is for some applications advantageous, it has for other applications the disadvantage of its severely inhibited crystallization capability. Up to now there has been no report on processes to obtain trehalulose-containing compositions, that means vitalose, which comprise both trehalulose and isomaltulose in significant amounts, and which allow the production thereof in an easy, inexpensive and commercially suitable way and which provide the advantage of its composition, in particular its ratio of trehalulose to isomaltulose, being adjustable according to the specific needs of the particular application of the produced trehalulose-containing composition, that means vitalose. Furthermore, there is the need in the art to provide improved means and methods for the prophylaxes and treatment of conditions and diseases related to the glucose and/or insulin metabolism in the human or animal body, in particular for specific groups of patients, which up to now have not been considered to be suitable for being supplied with a carbohydrate, in particular sugar-containing diet.